<!doctype html>
<html>

<head>
    <meta charset="utf-8">
    <title>display:flex水平排列</title>
    <style>
        .display-flex {
            display: flex;
        }

        .div-size {
            border: 1px solid red;
            width: 200px;
            height: 120px;
            margin: 10px;
        }
    </style>
</head>

<body>
    <div class="display-flex">
        <div class="div-size">1</div>
        <div class="div-size">2</div>
        <div class="div-size">3</div>
    </div>
</body>

</html>